Portable electronic devices, such as portable media players, tablet, netbook, and laptop computers, cell, media, and smart phones, have become ubiquitous in recent years. These devices often include an audio jack through which they receive and provide audio information. The audio jacks may include, or be connected to, electronic circuits such as audio drivers for driving headphones or speakers, audio receivers for receiving audio signals from a microphone, and others. These audio jacks may be arranged to receive an audio plug that may be connected to headphones, speakers, microphones, or other equipment.
These audio plugs may be electrical audio plugs. That is, they may include a number of ring-shaped contacts along their lengths. These contacts may connect to conductors in a cable attached to the audio plug. These contacts may include contacts for left audio, right audio, ground, and microphone. These audio plugs may also be optical audio plugs, that is, they may have an opening at an end to transmit or receive optical signals. In such a situation, the audio plug may be formed of plastic or other nonconductive material. Accordingly, it may be desirable to be able to detect the presence of either electrical or optical audio plugs.
These audio jacks may also include an opening where an audio plug may be inserted by a user. Unfortunately, dust and other debris and particulate matter may enter the opening and foul the inside of an audio jack. This particulate matter may then hamper or impede the proper function of the audio jack.
Also, some electronic devices employing audio jacks may achieve great commercial success. As such, millions of these audio jacks may need to be manufactured. Due to the magnitude of this task, any simplification in the assembly process is multiplied the millions of times the audio jacks are assembled. Accordingly, it may be desirable to provide an audio jack that is readily manufactured.
Thus, what is needed are circuits, methods, and apparatus that may provide audio jacks having reliable detection of both electrical and optical audio plugs. It may also be desirable that these audio jacks be robust and durable, and be readily assembled.